Generally, devices or circuit patterns are not formed in an edge region of a semi-conductor substrate since the edge region is used for conveying the semiconductor substrate. However, undesired layers or particles can be deposited on the edge region of the semiconductor substrate during manufacturing processes. If the manufacturing processes are continued without removing the undesired layers or particles from the semiconductor substrate, the semiconductor substrate can be deformed, or the yield of the manufacturing can be reduced. In addition, it may be difficult to align the semi-conductor substrate due to the undesired layers or particles.
For these reasons, the undesired layers or particles deposited in the edge region of the substrate should be removed through a predetermined post process. For example, the undesired layers or particles can be removed from the edge region of the semiconductor substrate through a wet etch process using a predetermined chemical. Recently, however, plasma is selectively supplied to the edge region of the substrate to remove undesired layers or particles from the edge region of the semiconductor substrate.
A conventional etching apparatus for etching of an edge region of a semiconductor using plasma is disclosed in Korean Patent Publication No. 10-0635377. The plasma etching apparatus for edge region of the semiconductor in accordance with the Korean Patent Publication supplies reaction gas to a peripheral region of an insulation plate which has a shape corresponding to a non-etch region, i.e., a center region of a semiconductor substrate and is disposed thereabove. The plasma etching apparatus converts the reaction gas in the peripheral region of the insulation plate into plasma using an electrode portion which is disposed at an outer upper portion of a chamber, and removes layers or particles deposited in an edge region of the semiconductor substrate. However, it is difficult to concentrate plasma onto the edge region of the substrate since the electrode portion is disposed at the outer upper portion of the chamber.
In the above described conventional etching apparatus using only CCP, the CCP can penetrate from the edge region to the center region (non-etch region) of the semiconductor substrate, the reaction gas can be converted into CCP in the center region of the semiconductor substrate, or undesired arcing can occur. Furthermore, necessary layers formed on the center region (non-etch region) of the semiconductor substrate can be etched by reaction gas penetrated into the center region.
Furthermore, since the density of the CCP is low (i.e., the etch rate of the conventional etching apparatus is low), it takes much time to remove undesired layers or particles from the edge region of the semiconductor substrate. Moreover, some layers cannot be removed using the conventional etching apparatus.
In addition, due to a low process temperature, it is difficult to remove a metal layer from the edge region of the semiconductor substrate using the conventional etching apparatus. Particularly, some metal layers such as a copper (Cu) layer are not removed.
A semiconductor device is manufactured through a process of depositing or etching a predetermined layer on a semiconductor substrate. This process is performed inside a chamber, which is a closed type container having a unique process environment. Generally, a chuck, which is a unit fixing a semiconductor substrate, is installed inside the chamber to support a substrate loaded inside the chamber.
The chuck is classified into a mechanical chuck, a vacuum chuck, and an electrostatic chuck in accordance with a method for fixing a substrate. The electrostatic chuck fixes and supports a substrate using a voltage difference (static electricity) between the substrate and an electrode inside the chuck. Since the electrostatic chuck can maintain uniform gripping force, it is used for various chambers.
The electrostatic chuck is used for fixing a substrate also in a substrate edge etching apparatus configured to remove a layer or particles on a substrate edge region. However, the substrate edge etching apparatus should expose a substrate edge region and concentrate plasma on the exposed region. In accordance with a conventional electrostatic chuck, a single electrode is formed inside a ceramic, and direct current (DC) power or RF power is supplied to the electrode. Accordingly, the life of a coated layer on an electrostatic chuck body is reduced. Particularly, in a case where the electrostatic chuck is used for a substrate edge etching apparatus, plasma density on a substrate edge region is reduced, so that etching the substrate edge region is not efficiently performed, and a substrate central region, which is a non-etch region, is damaged by plasma.